The present invention relates to tape applicators and/or dispensers (collectively "applicators"), and more specifically, to a guard for preventing accidental injury from the cutting edge of the applicator blade.
Adhesive tape applicators are known in the art for applying a tape to a surface such as a carton or the like and can be hand held or be suitable for resting on a table. The hand-held applicators are particularly suited for applying a long length of tape to the object to be taped. Generally, the applicator consists of a handle supporting a tape spool and device to guide and dispense the tape. A frame is supported on the handle, and a cutting blade comprising a sharply serrated edge is mounted on the frame along a tape feed path. The serrated edge has teeth which project beyond an edge of the tape applicator frame. However, by design, it often occurs that the blade protrudes too far from the frame. As a result, the blade may cut or injure a user or the blade itself may be damaged through simple handling of the manual applicator as the blade bangs against some hard object. However, if the blade were not to extend fully from the applicator, the ability to cut the tape when desired as it passes through the applicator would be hampered.
To overcome these shortcomings, a retractable blade was developed to be mounted in the frame as known from U.S. Pat. No. 5,849,144. In this embodiment, the blade is specially mounted within the frame utilizing a complex screw and shield mechanism in which the blade is operatively connected to a manual tape applicator wiper so that when the wiper is pressed to wipe the tape against the surface being taped, it pushes the blade against the bias of a spring to extend from the frame to cut the tape.
Such a mechanism has been satisfactory. However, it suffers from a disadvantage that it requires a complex spring and lever mechanism to protect the blade from injurious contact to the user or injury or to the blade itself Furthermore, because the blade is activated by the wiper which extends at an angle from the top of the frame, over rotation of the handle of the applicator is required to cause the blade to extend sufficiently to cut which strains the wrist as a result of repeated use of such an applicator. Additionally, to extract a small piece of tape by hand is a complex movement as one hand holds the handle, the other hand pulls and rips the tape, while the wiper must be activated. Furthermore, conventional applicators are limited to serrated blades, because the use of an exposed knife blade or razor is considered too dangerous for the user.
A second structure for protecting the blade from injurious contact with the user or with some hard object is known from U.S. Pat. No. 4,818,329 which provides for a manually operable tape dispenser/applicator having a frame and a blade extending from the frame. A guard is mounted on a rotatable shaft within the frame and extends beyond the blade. A spring is mounted within the frame to bias the guard towards the blade. The guard also wipes the tape as it is applied to the surface. This applicator is less than satisfactory because it suffers from the disadvantage that it too requires a complex structure including shafts and biasing springs anchored well within the housing and cannot be retroactively fit into a standard applicator. It too utilizes a serrated blade.
With respect to the table-top models of tape applicators, much like the conventional scotch tape dispensers, they have a base, with a roll of tape mounted therein. As is known in the art, a blade is usually mounted on the base along a travel path of tape as it leaves the roller and extends above the frame to be exposed for cutting tape. Because of the exposed blade, it lends itself to accidental scraping or cutting of the user's hand as the user's hand slides across the blade. This problem becomes even more pronounced in industrial tape applicators where the blade is sturdier and longer, supplying more of a cutting surface lending itself to deeper cuts and larger cuts. Furthermore, because the blade is bigger, it is in effect more exposed.
Accordingly, it is desired to provide a tape applicator which provides protection for the blade in both a hand held or table top applicator which may be retroactively added to the applicator and is of simple construction.